CN107249946B - hybrid vehicle - Google Patents

Abstract

A control process including the following steps is performed. The control process includes a step of reducing the engine torque ( S102 ) when switching from the series-parallel mode to the series mode (YES in S100 ), a step of releasing the clutch ( C1 ) ( S104 ), reducing the first rotating electrical machine ( S104 ) The step ( S106 ) of the reaction torque of the first MG) and the step ( S108 ) of increasing the torque of the second rotary electric machine (the second MG), and the step of increasing the first synchronisation (YES in S110 ) The step of positive torque of the MG ( S112 ) and the step of starting to engage the clutch (CS) ( S114 ), and the rotational speed of the first rotary electric machine (first MG) and the rotational speed of the engine are synchronized with each other (YES in S116 ) Step ( S118 ) of engaging the clutch (CS) at the time.

Description

hybrid vehicle

technical field

The present invention relates to a hybrid vehicle, and more particularly, to a hybrid vehicle including first and second rotating electric machines and a transmission unit.

Background technique

A hybrid vehicle is known which includes not only an engine, two rotating electric machines, and a power split mechanism, but also a transmission mechanism between the engine and the power split mechanism.

A hybrid vehicle described in International Application Publication No. 2013/114594 employs a series-parallel hybrid system. In a vehicle having a series-parallel hybrid system, the power of the engine is transmitted to the first rotating electrical machine (first motor generator) and used to generate electricity, while part of the power of the engine is also transmitted to the drive wheels via the power split mechanism.

There is also known a hybrid vehicle having a configuration (series hybrid system) by which the hybrid vehicle generates electricity by using the power of an engine and travels in a series mode in which an electric motor is driven by the generated electricity. In such a series hybrid system, the power of the engine is not transmitted to the drive wheels.

Such a hybrid vehicle described in International Application Publication No. 2013/114594 cannot run in a series mode because when the power of the engine is transmitted to the first motor generator, the power of the engine is also transmitted to the driving wheels via the power split mechanism.

In this series-parallel hybrid system, there is a concern that tooth contact noise will occur in the gear mechanism provided in the drive system between the engine and the drive wheels due to torque fluctuation of the engine at low vehicle speeds, etc., so it is necessary to select the operation of the engine. point so that tooth contact noise does not occur and the engine can operate at operating points where fuel consumption is not optimal. Therefore, there is room for improvement in terms of fuel consumption.

On the other hand, in a series hybrid system, the engine is completely isolated from the gear mechanism provided in the drive system, so such tooth contact noise does not need to be considered so much. However, the series hybrid system is inferior in fuel consumption to the series hybrid system in terms of fuel consumption in the speed range where the engine's operating efficiency is high because the entire torque of the engine is once converted into electric power and then the electric power is converted back to the torque of the driving wheels by means of the electric motor. Parallel hybrid system.

In this way, there are points where series hybrid systems are superior to series and parallel hybrid systems, and there are also points where series and parallel hybrid systems are superior to series hybrid systems, so it is desirable to be configured to allow the selection of series in response to the conditions of the vehicle. mode and one of series-parallel mode.

Incidentally, when switching from the series-parallel mode to the series mode is achieved by, for example, engaging the clutch to directly couple the first motor generator to the engine, the power transmission state at the time of switching can be driven from the power between the engine and the drive wheels. The state of transmission between them is changed to a state in which power is isolated between the engine and the drive wheels. Therefore, the direct torque from the engine to the driving wheels is reduced, so that the driving force of the vehicle can be reduced before and after switching from the series-parallel mode to the series mode.

SUMMARY OF THE INVENTION

The present invention provides a hybrid vehicle that suppresses a decrease in driving force when a driving mode is switched from a series-parallel mode to a series mode.

One aspect of the present invention provides a hybrid vehicle. The hybrid vehicle includes an internal combustion engine, a first rotating electrical machine, a second rotating electrical machine, a power transmission unit, a differential unit, a clutch, and a controller. The second rotary electric machine is configured to output power to the drive wheels. The power transmission unit includes an input element and an output element. The input element is configured to receive power from the internal combustion engine. The output element is configured to output power input to the input element. The power transmission unit is configured to switch between a non-neutral state, in which power is transmitted between the input member and the output member, and a neutral state, in which the neutral state is , no power is transmitted between the input element and the output element. The differential unit includes a first rotation element, a second rotation element and a third rotation element. The first rotary element is connected to the first rotary electric machine. The second rotary element is connected to the second rotary electric machine and the drive wheel. The third rotation element is connected to the output element. The differential unit is configured such that: when the rotational speed of any two of the first rotation element, the second rotation element, and the third rotation element is determined, the first rotation element, the second rotation element, and the third rotation element The rotational speed of the remaining one of the second rotating element and the third rotating element is determined. The clutch is configured to switch between an engaged state, in which power is transmitted from the internal combustion engine to the first rotating electrical machine, and a released state, in which transmission from the internal combustion engine to the first rotating electrical machine is interrupted. The transmission of the power of the first rotating electrical machine is described. Power from the internal combustion engine is transmitted to the first rotating electrical machine through at least one of a first path or a second path. The first path is a path through which power is transmitted from the internal combustion engine to the first rotating electrical machine via the power transmission unit and the differential unit, and the second path is a path through which power is transmitted from the internal combustion engine via and A path different from the first path is transmitted to a path through which the first rotating electrical machine passes. The clutch is disposed in the second path. The controller is configured to control the second rotating electrical machine after starting to control the power transmission unit to place the power transmission unit in the neutral state when switching from the series-parallel mode to the series mode so that the output torque of the second rotating electrical machine is increased. The series-parallel mode is a mode in which the clutch is in the released state and the power transmission unit is in the non-neutral state. The series mode is a mode in which the clutch is in the engaged state and the power transmission unit is in the neutral state.

With the hybrid vehicle thus configured, the direct torque from the internal combustion engine to the drive wheels via the power transmission unit, which increases as the power transmission unit gets closer to the neutral state, can be compensated for by increasing the output torque of the second rotating electrical machine. decrease. Therefore, it is possible to suppress the reduction in the driving force of the vehicle when the driving mode is switched from the series-parallel mode to the series mode.

In the hybrid vehicle, the controller may be configured to control at least any one of the first rotating electrical machine and the second rotating electrical machine until the clutch is placed in the engaged state to The torque ripple that occurs as a result of placing the clutch in the engaged state is reduced.

With the hybrid vehicle thus configured, it is possible to suppress the transmission of shock due to placing the clutch in the engaged state to the drive wheels via the differential unit. Therefore, the occurrence of shock can be suppressed when switching from the series-parallel mode to the series mode.

The controller may be configured to place the power transfer unit in the neutral state and reduce the output torque of the internal combustion engine when switching from the series-parallel mode to the series mode. With the hybrid vehicle thus configured, unnecessary increase in the rotational speed of the internal combustion engine can be suppressed.

With the hybrid vehicle thus configured, an unnecessary increase in the rotational speed of the internal combustion engine can be suppressed.

With the hybrid vehicle thus constructed, the direct torque from the internal combustion engine to the drive wheels via the power transmission unit, which increases as the power transmission unit gets closer to the neutral state, can be compensated for by increasing the output torque of the second rotating electrical machine. decrease. Therefore, it is possible to provide a hybrid vehicle that suppresses a decrease in driving force when the driving mode is switched from the series-parallel mode to the series mode.

Description of drawings

The features, advantages, and technical and industrial implications of exemplary embodiments of the present invention will be described hereinafter with reference to the accompanying drawings, in which like reference numerals refer to like elements, and wherein:

1 is a view showing the overall configuration of a hybrid vehicle including a drive system according to an embodiment of the present invention;

FIG. 2 is a block diagram schematically showing power transmission paths of components of the vehicle in FIG. 1;

FIG. 3 is a block diagram showing the configuration of a controller for the vehicle in FIG. 1;

FIG. 4 is a view schematically showing the configuration of a hydraulic circuit mounted on the hybrid vehicle shown in FIG. 1;

5 is a graph showing each driving mode in the hybrid vehicle and the controlled state of the clutches and brakes of the transmission unit in each driving mode;

FIG. 6 is a nomogram in a single-motor EV mode, which is one of the drive modes shown in FIG. 5;

FIG. 7 is a nomogram in a dual-motor EV mode, which is one of the drive modes shown in FIG. 5;

8 is a nomogram in a series-parallel HV mode as one of the drive modes shown in FIG. 5;

FIG. 9 is a nomogram in the series HV mode as one of the drive modes shown in FIG. 5;

FIG. 10 is a view showing a casing structure of the drive system shown in FIG. 1;

11 is a flowchart illustrating a control process of synchronization control performed by a controller according to an embodiment;

12 is a nomogram for illustrating a process of synchronization control according to an embodiment;

13 is a sequence diagram for illustrating a process of synchronization control according to an embodiment;

14 is a timing chart for illustrating a procedure of synchronization control in a case where the engagement timing of the clutch CS is changed according to an alternative embodiment of the embodiment;

15 is a timing chart for illustrating a control process in a case where shock reduction control for reducing shock upon clutch engagement is performed together with synchronization control according to another alternative embodiment of the embodiment;

16 is a graph showing the controlled state of the clutches and brakes of the transmission unit in each drive mode according to yet another alternative embodiment of the embodiment;

FIG. 17 is a nomogram for illustrating the operation of the E4 row and the E5 row among the drive modes according to the alternative embodiment shown in FIG. 16;

FIG. 18 is a nomogram for illustrating operations of rows H6 to H8 among the drive modes according to the alternative embodiment shown in FIG. 16;

FIG. 19 is a view showing a first alternative embodiment of the gear mechanism of the hybrid vehicle shown in FIG. 1; and

FIG. 20 is a view showing a second alternative embodiment of the gear mechanism of the hybrid vehicle shown in FIG. 1 .

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The same reference numerals refer to the same or corresponding parts in the following embodiments, and the description thereof will not be repeated.

FIG. 1 is a view showing the overall configuration of a hybrid vehicle including a drive system according to an embodiment of the present invention.

As shown in FIG. 1 , a hybrid vehicle 1 (hereinafter also referred to as vehicle 1 ) includes an engine 10 , a drive system 2 , drive wheels 90 and a controller 100 . The drive system 2 includes a first motor generator (hereinafter referred to as a first MG) 20 as a first rotary electric machine, a second motor generator (hereinafter referred to as a second MG) 30 as a second rotary electric machine, and a speed change unit 40 , the differential unit 50 , the clutch CS, the input shaft 21 , the countershaft 70 as the output shaft of the drive system 2 , the differential gear set 80 and the hydraulic circuit 500 .

The hybrid vehicle 1 is a front-engine front-wheel drive (FF) hybrid vehicle that travels by using the power of at least one of the engine 10 , the first MG 20 and the second MG 30 . The hybrid vehicle 1 may be a plug-in hybrid vehicle in which an on-board battery (not shown) is rechargeable from an external power source.

The engine 10 is, for example, an internal combustion engine such as a gasoline engine and a diesel engine. Each of the first MG 20 and the second MG 30 is, for example, a permanent magnet synchronous motor including a rotor in which permanent magnets are embedded. The drive system 2 is a biaxial drive system in which the first MG 20 is arranged coaxially with the crankshaft of the engine 10 along the first axis 12 and the second MG 30 is arranged along a different axis from the first axis 12 The second axis 14 is provided. The first axis 12 and the second axis 14 are parallel to each other.

The transmission unit 40 , the differential unit 50 and the clutch CS are further arranged along the first axis 12 . The transmission unit 40 , the differential unit 50 , the first MG 20 and the clutch CS are arranged in the stated order from the side closer to the engine 10 .

The first MG 20 is provided so as to receive power from the engine 10 . More specifically, the input shaft 21 of the drive system 2 is connected to the crankshaft of the engine 10 . The input shaft 21 extends in a direction away from the engine 10 along the first axis 12 . The input shaft 21 is connected to the clutch CS at its distal end extending from the engine 10 . The rotation shaft 22 of the first MG 20 extends along the first axis 12 in a cylindrical shape. The input shaft 21 passes through the inside of the rotating shaft 22 at a portion before the input shaft 21 is connected to the clutch CS. The input shaft 21 is connected to the rotation shaft 22 of the first MG 20 via the clutch CS.

The clutch CS is provided in the power transmission path from the engine 10 to the first MG 20 . The clutch CS is a hydraulic friction engagement element capable of coupling the input shaft 21 to the rotating shaft 22 of the first MG 20 . When the clutch CS is placed in the engaged state, the input shaft 21 and the rotating shaft 22 are coupled to each other, and power is allowed to be transmitted from the engine 10 to the first MG 20 . When the clutch CS is placed in the released state, the coupling of the input shaft 21 and the rotary shaft 22 is released, and the transmission of power from the engine 10 to the first MG 20 via the clutch CS is interrupted.

The shifting unit 40 shifts the power from the engine 10 and then outputs the power to the differential unit 50 . The transmission unit 40 includes a single pinion type planetary gear mechanism, a clutch C1 and a brake B1. The single-pinion type planetary gear mechanism includes a sun gear S1, a pinion gear P1, a ring gear R1, and a carrier CA1.

The sun gear S1 is arranged such that the rotation center of the sun gear S1 coincides with the first axis 12 . The ring gear R1 is provided coaxially with the sun gear S1 on the radially outer side of the sun gear S1. The pinion gear P1 is arranged between the sun gear S1 and the ring gear R1, and meshes with the sun gear S1 and the ring gear R1. The pinion P1 is rotatably supported by the carrier CA1. The carrier CA1 is connected to the input shaft 21 and rotates integrally with the input shaft 21 . Each pinion gear P1 is provided so as to be able to revolve around the first axis 12 and to be able to autorotate around the central axis of the pinion gear P1.

As shown in FIGS. 6 to 9 , 17 , and 18 (described later), the rotational speed of the sun gear S1 , the rotational speed of the carrier CA1 (ie, the rotational speed of the engine 10 ) and the rotational speed of the ring gear R1 are in the range determined by each The relationship represented by the points connected by the straight lines in the nomogram (ie, the relationship in which when any two rotational speeds are determined, the remaining one is also determined).

In the present embodiment, the carrier CA1 is provided as an input element to which power is input from the engine 10, and the ring gear R1 is provided as an output element that outputs the power input to the carrier CA1. By using this planetary gear mechanism including the sun gear S1, the pinion gear P1, the ring gear R1, and the carrier CA1, the power input to the carrier CA1 is shifted and output from the ring gear R1.

The clutch C1 is a hydraulic friction engagement element capable of coupling the sun gear S1 to the planet carrier CA1. When the clutch C1 is placed in the engaged state, the sun gear S1 and the carrier CA1 are coupled to each other and rotate integrally with each other. When the clutch C1 is placed in the released state, the integral rotation of the sun gear S1 and the carrier CA1 is canceled.

The brake B1 is a hydraulic friction engagement element capable of restricting (locking) the rotation of the sun gear S1 . When the brake B1 is placed in the engaged state, the sun gear S1 is fixed to the casing of the drive system, and the rotation of the sun gear S1 is restricted. When the brake B1 is placed in a released state (disengaged state), the sun gear S1 is separated from the housing of the drive system, and the rotation of the sun gear S1 is allowed.

The speed ratio of the speed change unit 40 (the ratio of the rotational speed of the carrier CA1 as the input element to the rotational speed of the ring gear R1 as the output element, specifically, the rotational speed of the carrier CA1/the rotational speed of the ring gear R1) is responsive to the clutch C1 and the brake The combination of the engaged/released state of B1 changes. When the clutch C1 is engaged and the brake B1 is released, a low gear position Lo with a speed ratio of 1.0 (direct-coupling state) is established. When the clutch C1 is released and the brake B1 is engaged, a high gear Hi with a speed ratio less than 1.0 (eg, 0.7, a so-called overdrive state) is established. When the clutch C1 is engaged and the brake B1 is engaged, the rotation of the sun gear S1 and the rotation of the carrier CA1 are restricted, and thus the rotation of the ring gear R1 is also restricted.

The transmission unit 40 is configured to be switchable between a non-neutral state and a neutral state. In a non-neutral state, power is delivered. In neutral, power is not delivered. In the present embodiment, the above-described direct coupling state and overdrive state correspond to a non-neutral state. On the other hand, when both the clutch C1 and the brake B1 are released, the carrier CA1 is allowed to inertially slide about the first axis 12 . Thus, a neutral state is obtained in which the power transmitted from the engine 10 to the carrier CA1 is not transmitted from the carrier CA1 to the ring gear R1.

The differential unit 50 includes a single pinion type planetary gear mechanism and an auxiliary drive gear 51 . The single-pinion type planetary gear mechanism includes a sun gear S2, a pinion gear P2, a ring gear R2, and a carrier CA2.

The sun gear S2 is arranged such that the rotation center of the sun gear S2 coincides with the first axis 12 . The ring gear R2 is provided coaxially with the sun gear S2 on the radially outer side of the sun gear S2. The pinion gear P2 is arranged between the sun gear S2 and the ring gear R2, and meshes with the sun gear S2 and the ring gear R2. The pinion P2 is rotatably supported by the carrier CA2. The carrier CA2 is connected to the ring gear R1 of the speed change unit 40, and rotates integrally with the ring gear R1. Each pinion gear P2 is provided so as to be able to revolve around the first axis 12 and to be able to autorotate around the central axis of the pinion gear P2.

The rotation shaft 22 of the first MG 20 is connected to the sun gear S2. The rotation shaft 22 of the first MG 20 rotates integrally with the sun gear S2. The secondary drive gear 51 is connected to the ring gear R2. The auxiliary drive gear 51 is the output gear of the differential unit 50 . The output gear rotates integrally with the ring gear S2.

As shown in FIGS. 6 to 9 , 17 , and 18 , the rotational speed of the sun gear S2 (ie, the rotational speed of the first MG 20 ), the rotational speed of the carrier CA2 , and the rotational speed of the ring gear R2 are in each of the nomograms The relationship represented by the points connected by the straight line (that is, when any two rotation speeds are determined, the remaining one rotation speed is also determined). Therefore, when the rotational speed of the carrier CA2 is a predetermined value, the rotational speed of the ring gear R2 can be varied steplessly by adjusting the rotational speed of the first MG 20 .

In the present embodiment, the case where the differential unit 50 is formed by the planetary gear mechanism is described. However, the differential unit 50 is not limited to this configuration. Any configuration of the differential unit 50 is applicable as long as the differential unit 50 is configured such that when the rotational speed of any two of the three rotating elements is determined, the rotational speed of the remaining one of the three rotating elements is determined . For example, the differential unit 50 may have a gear structure similar to a differential gear set.

The layshaft 70 extends parallel to the first axis 12 and the second axis 14 . The secondary shaft 70 is arranged parallel to the rotation axis 22 of the first MG 20 and the rotation axis 31 of the second MG 30 . A driven gear 71 and a drive gear 72 are provided on the counter shaft 70 . The driven gear 71 meshes with the secondary drive gear 51 of the differential unit 50 . That is, the power of the engine 10 and the power of the first MG 20 are transmitted to the counter shaft 70 via the auxiliary drive gear 51 of the differential unit 50 .

The transmission unit 40 and the differential unit 50 are connected in series with each other in a power transmission path from the engine 10 to the countershaft 70 . Therefore, the power from the engine 10 is shifted in the transmission unit 40 and the differential unit 50 and then transmitted to the countershaft 70 .

The driven gear 71 meshes with the reduction gear 32 connected to the rotation shaft 31 of the second MG 30 . That is, the power of the second MG 30 is transmitted to the counter shaft 70 via the reduction gear 32 .

The drive gear 72 meshes with the differential ring gear 81 of the differential gear set 80 . The differential gear set 80 is connected to left and right drive wheels 90 via corresponding left and right drive shafts 82 . That is, the rotation of the counter shaft 70 is transmitted to the left and right drive shafts 82 via the differential gear set 80 .

With the above-described configuration provided with the clutch CS, the hybrid vehicle 1 is allowed to operate in the mode using the series-parallel system (hereinafter referred to as the series-parallel mode), and is also allowed to operate in the mode using the series system (hereinafter referred to as the series mode) run under. In this regard, how power is transferred from the engine in each mode will be described with reference to the schematic diagram shown in FIG. 2 .

FIG. 2 is a block diagram schematically showing power transmission paths of components of the vehicle in FIG. 1 . As shown in FIG. 2 , the hybrid vehicle 1 includes an engine 10 , a first MG 20 , a second MG 30 , a transmission unit 40 , a differential unit 50 , a battery 60 , and a clutch CS.

The second MG 30 is provided such that power can be output to the drive wheels 90 . The transmission unit 40 includes input elements and output elements. The power of the engine 10 is input to this input element. The output element will input to the power output of the input element. The transmission unit 40 is configured to be switchable between a non-neutral state and a neutral state. In a non-neutral state, power is transferred between the input member and the output member. In the neutral state, no power is transmitted between the input element and the output element.

The battery 60 supplies electric power to the corresponding first MG 20 or the second MG 30 during cranking of one of the first MG 20 and the second MG 30 and stores it during regeneration of the one of the first MG 20 and the second MG 30 Electric power generated by the corresponding first MG 20 or second MG 30 .

The differential unit 50 includes a first rotation element, a second rotation element, and a third rotation element. The first rotary element is connected to the first MG 20 . The second rotation element is connected to the second MG 30 and the driving wheel 90 . The third rotation element is connected to the output element of the speed change unit 40 . The differential unit 50 is constructed as in the case of a planetary gear mechanism or the like so that when the rotational speed of any two of the first to third rotational elements is determined, the rotational speed of the remaining one of the first to third rotational elements is determined .

The hybrid vehicle 1 is configured to be able to transmit power from the engine 10 to the first MG 20 using at least any one of the two paths K1 , K2 in which power is transmitted. The path K1 is a path through which power is transmitted from the engine 10 to the first MG 20 via the transmission unit 40 and the differential unit 50 . The path K2 is different from the path K1 and is a path through which power is transmitted from the engine 10 to the first MG 20 . The clutch CS is provided in the path K2 and is switchable between an engaged state and a released state. In the engaged state, power is transmitted from the engine 10 to the first MG 20 . In the released state, power transmission from the engine 10 to the first MG 20 is interrupted.

In the HV mode in which the engine is running, either one of the clutch C1 and the brake B1 is placed in an engaged state, and the other of the clutch C1 and the brake B1 is placed in a released state. Thus, when the transmission unit 40 is controlled to the non-neutral state, power is transmitted from the engine 10 to the first MG 20 via the path K1. At this time, when the clutch CS is placed in the released state to interrupt the path K2 at this time, the vehicle can operate in the series-parallel mode.

On the other hand, in the HV mode in which the engine operates, when power is transmitted through the path K2 by directly coupling the engine 10 to the first MG 20 using the clutch CS and by controlling the transmission unit 40 so that the transmission unit 40 passes the clutch C1 and the brake When both B1 are placed in a released state and placed in a neutral state to interrupt path K1, the vehicle can operate in series mode. At this time, in the speed change unit 50, the rotating element connected to the speed change unit 40 can rotate freely, and thus the other two rotating elements do not affect each other and can rotate. Therefore, the operation of generating electricity by rotating the first MG 20 using the rotation of the engine 10 and the operation of rotating the driving wheels by driving the second MG 30 using the generated electric power or the electric power charged in the battery 60 can be independently performed. .

The speed change unit 40 is not always required to be able to change the speed ratio. Only the clutch is applicable as long as the power transmission between the engine 10 and the differential unit 50 in the path K1 can be interrupted.

FIG. 3 is a block diagram showing the configuration of the controller 100 of the vehicle shown in FIG. 1 . As shown in FIG. 3 , the controller 100 includes an HV ECU 150 , an MG ECU 160 and an engine ECU 170 . Each of the HV ECU 150, the MG ECU 160, and the engine ECU 170 is an electronic control unit including a computer. The number of ECUs is not limited to three. An integrated single ECU may be provided as a whole, or two or more separate ECUs may be provided.

The MG ECU 160 controls the first MG 20 and the second MG 30 . The MG ECU 160 controls the output torque of the first MG 20 by, for example, adjusting the current value supplied to the first MG 20 , and controls the output torque of the second MG 30 by adjusting the current value supplied to the second MG 30 .

The engine ECU 170 controls the engine 10 . The engine ECU 170 controls, for example, the opening degree of the electronic throttle valve of the engine 10 , controls ignition of the engine by outputting an ignition signal, or controls fuel injection to the engine 10 . The engine ECU 170 controls the output torque of the engine 10 through electronic throttle opening control, injection control, ignition control, and the like.

The HV ECU 150 comprehensively controls the entire vehicle. A vehicle speed sensor, accelerator operation amount sensor, MG1 rotational speed sensor, MG2 rotational speed sensor, output shaft rotational speed sensor, battery sensor, and the like are connected to this HV ECU 150 . Through these sensors, the HV ECU 150 acquires the vehicle speed, the accelerator operation amount, the rotational speed of the first MG 20, the rotational speed of the second MG 30, the rotational speed of the output shaft of the power transmission system, the battery state SOC, and the like.

The HV ECU 150 calculates required driving force, required power, required torque, etc. for the vehicle based on the acquired information. The HV ECU 150 determines the output torque of the first MG 20 (hereinafter also referred to as MG1 torque), the output torque of the second MG 30 (hereinafter also referred to as MG2 torque) and the engine 10 based on the calculated request values output torque (hereinafter also referred to as engine torque). The HV ECU 150 outputs the command value of the MG1 torque and the command value of the MG2 torque to the MG ECU 160 . The HV ECU 150 outputs the command value of the engine torque to the engine ECU 170 .

The HV ECU 150 controls the clutches C1, CS, and the brake B1 based on a drive mode (described later) and the like. The HV ECU 150 outputs, to the hydraulic circuit 500 shown in FIG. 1 , a command value of the hydraulic pressure supplied to the clutch C1 ( PbC1 ), a command value of the hydraulic pressure supplied to the clutch CS (PbCS), and a command value of the hydraulic pressure supplied to the brake B1 ( PbB1). The HV ECU 150 outputs the control signal NM and the control signal S/C to the hydraulic circuit 500 shown in FIG. 1 .

The hydraulic circuit 500 shown in FIG. 1 controls the hydraulic pressures supplied to the clutch C1 and the brake B1, respectively, in response to the command value PbC1 and the command value PbB1, controls the electric oil pump in response to the control signal NM, and controls whether the pair is allowed or not in response to the control signal S/C. Simultaneous engagement of the clutch C1, the brake B1 and the clutch CS is prohibited for control.

Next, the configuration of the hydraulic circuit will be described. FIG. 4 is a view schematically showing the configuration of the hydraulic circuit 500 mounted on the hybrid vehicle 1 . The hydraulic circuit 500 includes a mechanical oil pump (hereinafter also referred to as MOP) 501; an electric oil pump (hereinafter also referred to as EOP) 502; pressure regulating valves 510, 520; linear solenoid valves SL1, SL2, SL3; 550; electromagnetic switching valve 560; check valve 570; and oil passages LM, LE, L1, L2, L3, L4.

The MOP 501 is driven by the rotation of the carrier CA2 of the differential unit 50 to generate hydraulic pressure. Therefore, when the carrier CA2 is rotated by, for example, driving the engine 10, the MOP 501 is also driven; conversely, when the carrier CA2 is stopped, the MOP 501 is also stopped. This MOP 501 outputs the generated hydraulic pressure to the oil passage LM.

The hydraulic pressure in the oil passage LM is regulated (reduced) to a predetermined pressure by the pressure regulating valve 510 . Hereinafter, the hydraulic pressure in the oil passage LM regulated by the pressure regulating valve 510 is also referred to as the line pressure PL. The line pressure LP is supplied to each of the linear solenoid valves SL1, SL2, SL3.

The linear solenoid valve SL1 generates hydraulic pressure (hereinafter referred to as C1 pressure) for engaging the clutch C1 by adjusting the line pressure PL in response to the hydraulic pressure command value PbC1 from the controller 100 . This C1 pressure is supplied to the clutch C1 via the oil passage L1.

The linear solenoid valve SL2 generates hydraulic pressure for engaging the brake B1 (hereinafter referred to as the B1 pressure) by adjusting the line pressure PL in response to the hydraulic pressure command value PbB1 from the controller 100 . This B1 pressure is supplied to the brake B1 via the oil passage L2.

The linear solenoid valve SL3 generates a hydraulic pressure (hereinafter referred to as CS pressure) for engaging the clutch CS by adjusting the line pressure PL in response to the hydraulic pressure command value PbCS from the controller 100 . This CS pressure is supplied to the clutch CS via the oil passage L3.

The simultaneous supply prevention valve 530 is provided in the oil passage L1, and is configured to prevent the clutch C1 from being simultaneously engaged with at least one of the brake B1 and the clutch CS. Specifically, the oil passages L2 , L3 are connected to the simultaneous supply prevention valve 530 . The simultaneous supply prevention valve 530 operates by using the B1 pressure and the CS pressure passing through the oil passages L2, L3 as signal pressures.

When the two signal pressures as the B1 pressure and the CS pressure are not input to the simultaneous supply prevention valve 530 (ie, when both the brake B1 and the clutch CS are released), the simultaneous supply prevention valve 530 is at the C1 pressure and is supplied to the Normal state of clutch C1. FIG. 4 illustrates the case where the simultaneous supply preventing valve 530 is in a normal state.

On the other hand, when at least one of the signal pressures as the B1 pressure and the CS pressure is input to the simultaneous supply prevention valve 530 (ie, when at least one of the brake B1 and the clutch CS is engaged), even when the clutch C1 is engaged, The simultaneous supply prevention valve 530 is also switched to a discharge state in which the supply of the C1 pressure to the clutch C1 is cut off and the hydraulic pressure in the clutch C1 is released to the outside. Thus, the clutch C1 is released, so the clutch C1 is prevented from being simultaneously engaged with at least one of the brake B1 and the clutch CS.

Similarly, the simultaneous supply prevention valve 540 operates in response to the C1 pressure and the CS pressure as signal pressures to prevent the brake B1 from being simultaneously engaged with at least one of the clutch C1 and the clutch CS. Specifically, when the two signal pressures as the C1 pressure and the CS pressure are not input to the simultaneous supply prevention valve 540, the simultaneous supply prevention valve 540 is in a normal state in which the B1 pressure is supplied to the brake B1. On the other hand, when at least one of the signal pressures as the C1 pressure and the CS pressure is input to the simultaneous supply prevention valve 540, the simultaneous supply prevention valve 540 is switched to the discharge state, in which the B1 of the brake B1 is switched to the discharge state. The supply of pressure is cut off and the hydraulic pressure in the brake B1 is released to the outside. FIG. 4 illustrates a case where the C1 pressure is input as a signal pressure to the simultaneous supply preventing valve 540 and the simultaneous supply preventing valve 540 is in a discharge state.

Similarly, the simultaneous supply prevention valve 550 operates to prevent the clutch CS from being simultaneously engaged with at least one of the clutch C1 and the brake B1 by using the C1 pressure and the B1 pressure as signal pressures. Specifically, when the two signal pressures as the C1 pressure and the B1 pressure are not input to the simultaneous supply prevention valve 550, the simultaneous supply prevention valve 550 is in a normal state in which the CS pressure is supplied to the clutch CS. On the other hand, when at least one of the signal pressures as the C1 pressure and the B1 pressure is input to the simultaneous supply preventing valve 550, the simultaneous supply preventing valve 550 is switched to the discharge state in which the CS of the clutch CS is The supply of pressure is cut off and the hydraulic pressure in the clutch CS is released to the outside. FIG. 4 illustrates a case where the C1 pressure is input to the simultaneous supply preventing valve 550 and the simultaneous supply preventing valve 550 is in a discharge state.

The EOP 502 is driven by a motor (hereinafter also referred to as an internal motor) 502A provided inside to generate hydraulic pressure. The internal motor 502A is controlled by the control signal NM from the controller 100 . Therefore, the EOP 502 can operate regardless of whether the carrier CA2 is rotating. The EOP 502 outputs the generated hydraulic pressure to the oil circuit LE.

The hydraulic pressure in the oil passage LE is regulated (reduced) to a predetermined pressure by the pressure regulating valve 520 . The oil passage LE is connected to the oil passage LM via a check valve 520 . When the hydraulic pressure in the oil passage LE is higher than the hydraulic pressure in the oil passage LM by a predetermined pressure or more, the check valve 570 is opened, and the hydraulic pressure in the oil passage LE is supplied to the oil passage LM via the check valve 570 . Thus, also during the stop of the MOP 501 , the hydraulic pressure can be supplied to the oil passage LM by driving the EOP 502 .

The electromagnetic switching valve 560 is switched to any one of the open state and the closed state in response to the control signal S/C from the controller 100 . In the open state, the electromagnetic switching valve 560 communicates the oil passage LE and the oil passage L4. In the closed state, the electromagnetic switching valve 560 interrupts the oil passage LE from the oil passage L4, and releases the hydraulic pressure in the oil passage L4 to the outside. FIG. 4 illustrates a case where the electromagnetic switching valve 560 is in a closed state.

The oil passage L4 is connected to the simultaneous supply prevention valves 530 , 540 . When the electromagnetic switching valve 560 is in the open state, the hydraulic pressure in the oil passage LE is input as a signal pressure to the simultaneous supply prevention valves 530 and 540 via the oil passage L4. When the signal pressure from the oil passage L4 is input to the simultaneous supply preventing valve 530, the simultaneous supply preventing valve 530 is forcibly fixed to the normal state regardless of whether the signal pressure (B1 pressure) is input from the oil passage L2. Similarly, when the signal pressure is input from the oil circuit L4 to the simultaneous supply preventing valve 540, regardless of whether the signal pressure (C1 pressure) is input from the oil circuit L1, the simultaneous supply preventing valve 540 is forcibly fixed to the normal state. Therefore, by driving the EOP 502 and switching the electromagnetic switching valve 560 to the open state, the simultaneous supply prevention valves 530, 540 are simultaneously fixed to the normal state. Thus, the clutch C1 and the brake B1 are allowed to engage simultaneously, and a dual-motor mode (described later) is realized.

Hereinafter, the details of the control modes of the hybrid vehicle 1 will be described with reference to the operation engagement chart and the nomogram.

FIG. 5 is a graph showing each driving mode and the controlled state of the clutch C1 and the brake B1 of the transmission unit 40 in each driving mode.

The controller 100 causes the hybrid vehicle 1 to run in a motor drive mode (hereinafter referred to as an EV mode) or a hybrid mode (hereinafter referred to as an HV mode). This EV mode is a control mode in which the engine 10 is stopped and the hybrid vehicle 1 is caused to run by using the power of at least one of the first MG 20 and the second MG 30 . This HV mode is a control mode in which the hybrid vehicle 1 is caused to run by using the power of the engine 10 and the power of the second MG 30 . Each of EV mode and HV mode is further divided into some control modes.

In FIG. 5, C1, B1, CS, MG1, and MG2 represent clutch C1, brake B1, clutch CS, first MG 20, and second MG 30, respectively. A circle mark (O) in each of the C1 column, B1 column, and CS column indicates an engaged state, a cross mark (x) indicates a released state, and a triangle mark (Δ) indicates that any one of the clutch C1 and the brake B1 is in the engine braking state. is engaged during movement. The symbol G in each of the MG1 column and the MG2 column indicates that MG1 or MG2 operates primarily as a generator. The symbol M in each of the MG1 column and the MG2 column indicates that the MG1 or MG2 operates mainly as a motor.

In the EV mode, the controller 100 selectively switches between the single-motor mode and the dual-motor mode in response to a user's requested torque or the like. In the single-motor mode, the hybrid vehicle 1 is caused to run by using only the power of the second MG 30 . In the dual motor mode, the hybrid vehicle 1 is caused to run by using the power of both the first MG 20 and the second MG 30 .

When the load of the drive system 2 is low, the single motor mode is used. When the load of the drive system 2 becomes high, the drive mode is changed to the dual motor mode.

As shown in line E1 of FIG. 5 , when the hybrid vehicle 1 is driven (forward or reverse movement) in the single-motor EV mode, the controller 100 places the transmission unit 40 in neutral by releasing the clutch C1 and releasing the brake B1 state (state of no power transmission). At this time, the controller 100 causes the first MG 20 to operate mainly as a fixing device for fixing the rotational speed of the sun gear S2 to zero, and causes the second MG 30 to operate mainly as a motor (see FIG. 6 (described later) ). In order to cause the first MG 20 to operate as a stationary device, the current of the first MG 20 may be controlled by feeding back the rotational speed of the first MG 20 so that the rotational speed becomes zero. When the rotational speed of the first MG 20 is kept at zero, even when the torque is zero, the cogging torque can be utilized without increasing the current. When the transmission unit 40 is placed in the neutral state, the engine 10 does not co-rotate during braking, so the loss is reduced by this amount, and a large amount of regenerative power can be recovered.

As shown in row E2 in FIG. 5 , when the hybrid vehicle 1 is braked in the single-motor EV mode and engine braking is required, the controller 100 engages either of the clutch C1 and the brake B1 . For example, engine braking is used together with regenerative braking when the braking force is insufficient with only regenerative braking. For example, when the SOC of the battery is close to a fully charged state, the regenerative power cannot be charged, so it is conceivable to establish an engine braking state.

By engaging either of the clutch C1 and the brake B1, a so-called engine braking state is established. In the engine braking state, the rotation of the drive wheels 90 is transmitted to the engine 10, and then the engine 10 is rotated. At this time, the controller 100 causes the first MG 20 to operate mainly as a motor, and causes the second MG 30 to operate mainly as a generator.

On the other hand, as shown in row E3 in FIG. 5 , when the hybrid vehicle 1 is driven (forward or reverse movement) in the dual-motor EV mode, the controller 100 limits (locks) by engaging the clutch C1 and engaging the brake B1 ) of the rotation of the ring gear R1 of the speed change unit 40 . Thus, the rotation of the carrier CA2 of the differential unit 50 coupled to the ring gear R1 of the transmission unit 40 is also restricted (locked), so the carrier CA2 of the differential unit 50 is kept in a stopped state (engine speed Ne=0). The controller 100 causes the first MG 20 and the second MG 30 to operate mainly as electric motors (see FIG. 7 (described later)).

In the EV mode (single-motor mode or dual-motor mode), the engine 10 is stopped, and therefore the MOP 501 is also stopped. Therefore, in the EV mode, the clutch C1 or the brake B1 is engaged by using the hydraulic pressure generated by the EOP 502 .

In the HV mode, the controller 100 causes the first MG 20 to operate primarily as a generator, and causes the second MG 30 to operate primarily as a motor.

In the HV mode, the controller 100 sets the control mode to either a series-parallel mode or a series mode.

In the series-parallel mode, a part of the power of the engine 10 is used for driving the driving wheels 90 , and the rest of the power of the engine 10 is used as the power to generate electricity in the first MG 20 . The second MG 30 drives the driving wheels 90 by using the electric power generated by the first MG 20 . In the series-parallel mode, the controller 100 changes the speed ratio of the transmission unit 40 in response to the vehicle speed.

When the hybrid vehicle 1 is caused to move forward in the mid-speed or low-speed range, the controller 100 establishes the low gear position Lo by engaging the clutch C1 and releasing the brake B1 as shown in row H2 in FIG. description) in the solid line). On the other hand, when the hybrid vehicle 1 is caused to move forward in the high speed range, the controller 100 establishes the high gear Hi by releasing the clutch C1 and engaging the brake B1 as shown in the line H1 in FIG. 5 (see FIG. 8 (later). dashed line in the description). The transmission unit 40 and the differential unit 50 as a whole operate as a continuously variable transmission, whether when a high gear is established or when a low gear is established.

When the hybrid vehicle 1 is reversed, the controller 100 engages the clutch C1 and releases the brake B1 as shown in line H3 in FIG. 5 . When there is a residual amount of the SOC of the battery, the controller 100 rotates the second MG 30 in the reverse direction by itself; conversely, when there is no residual amount of the SOC of the battery, the controller 100 uses the first MG 20 by operating the engine 10 to rotate Power is generated, and the second MG 30 is rotated in the reverse direction.

In the series mode, the entire power of the engine 10 is used as power for generating electricity with the first MG 20 . The second MG 30 drives the driving wheels 90 by using the electric power generated by the first MG 20 . In the series mode, when the hybrid vehicle 1 moves forward or when the hybrid vehicle 1 reverses, the controller 100 releases both the clutch C1 and the brake B1 and engages the clutch CS as shown in lines H4 and H5 in FIG. 9 (described later)).

In HV mode, the engine 10 is running, so the MOP 501 is also running. Therefore, in the HV mode, the clutch C1 , the clutch CS or the brake B1 is mainly engaged by using the hydraulic pressure generated by the MOP 501 .

Hereinafter, the state of the rotating element in each operation mode shown in FIG. 5 will be described with reference to the nomogram.

FIG. 6 is a nomogram in single-motor EV mode. FIG. 7 is a nomogram in the dual-motor EV mode. FIG. 8 is a nomogram in series-parallel mode. Figure 9 is a nomogram in series mode.

In FIGS. 6 to 9 , S1 , CA1 and R1 represent the sun gear S1 , the carrier CA1 and the ring gear R1 of the speed change unit 40 , respectively, and S2 , CA2 and R2 represent the sun gear S2 and the carrier CA2 of the differential unit 50 , respectively and ring gear R2.

The controlled state in the single-motor EV mode (row E1 in FIG. 5 ) will be described with reference to FIG. 6 . In the single-motor EV mode, the controller 100 releases the clutch C1 , the brake B1 , and the clutch CS of the transmission unit 40 , stops the engine 10 , and causes the second MG 30 to operate mainly as a motor. Therefore, in the single-motor EV mode, the hybrid vehicle 1 travels by using the torque of the second MG 30 (hereinafter referred to as the second MG torque Tm2).

At this time, the controller 100 performs feedback control on the torque of the first MG 20 (hereinafter referred to as the first MG torque Tm1 ) so that the rotational speed of the sun gear S2 becomes zero. Therefore, the sun gear S2 does not rotate. However, because the clutch C1 and the brake B1 of the transmission unit 40 are released, the rotation of the carrier CA2 of the differential unit 50 is not restricted. Therefore, the ring gear R2 and carrier CA2 of the differential unit 50 and the ring gear R1 of the transmission unit 40 rotate in the same direction as the second MG 30 in conjunction with the rotation of the second MG 30 (inertia slip).

On the other hand, since the engine 10 is stopped, the carrier CA1 of the transmission unit 40 is kept in a stopped state. The sun gear S1 of the speed change unit 40 rotates in conjunction with the rotation of the ring gear R1 in a direction opposite to the rotation direction of the ring gear R1 (inertia slips).

In order to decelerate the vehicle in the single-motor EV mode, engine braking is allowed to be triggered in addition to regenerative braking using the second MG 30 . In this case (row E2 in FIG. 5 ), by engaging either of the clutch C1 and the brake B1 , the engine 10 also rotates while the carrier CA2 is driven from the drive wheel 90 side, thus triggering engine braking.

Next, the controlled state in the dual-motor EV mode (row E3 in FIG. 5 ) will be described with reference to FIG. 7 . In the dual-motor EV mode, the controller 100 engages the clutch C1 and the brake B1 , releases the clutch CS, and stops the engine 10 . Therefore, the rotation of each of the sun gear S1 , the carrier CA1 , and the ring gear R1 of the speed change unit 40 is restricted so that the rotational speed becomes zero.

Because the rotation of the ring gear R1 of the speed change unit 40 is restricted, the rotation of the carrier CA2 of the differential unit 50 is also restricted (locked). In this state, the controller 100 causes the first MG 20 and the second MG 30 to operate mainly as electric motors. Specifically, the second MG 30 is rotated in the positive direction by setting the second MG torque Tm2 to a positive torque, and the first MG 20 is rotated in the positive direction by setting the first MG torque Tm1 to a negative torque. Negative up rotation.

When the rotation of the carrier CA2 is restricted by engaging the clutch C1, the first MG torque Tm1 is transmitted to the ring gear R2 by using the carrier CA2 as a support point. The first MG torque Tm1 (hereinafter referred to as the first MG transmission torque Tm1c) transmitted to the ring gear R2 acts in the forward direction, and is transmitted to the counter shaft 70 . Therefore, in the dual-motor EV mode, the hybrid vehicle 1 travels by using the first MG transmission torque Tm1c and the second MG torque Tm2. The controller 100 adjusts the distribution ratio between the first MG torque Tm1 and the second MG torque Tm2 so that the sum of the first MG transmission torque Tm1c and the second MG torque Tm2 satisfies the user's request torque.

The controlled state in the series-parallel HV mode (lines H1 to H3 in FIG. 5 ) will be described with reference to FIG. 8 . FIG. 8 illustrates the situation where the vehicle is traveling forward in a low gear Lo (see row H2 in FIG. 5 , and the shared solid line shown in the nomogram of S1 , CA1 and R1 in FIG. 8 ) and the vehicle is moving in a high gear The case of driving forward with the bit Hi (see row H1 in FIG. 5, and the shared dotted line shown in the nomogram of S1, CA1, and R1 in FIG. 8). For convenience of description, it is assumed that the rotational speed of the ring gear R1 is the same regardless of when the vehicle is traveling forward in the low gear position Lo or when the vehicle is traveling forward in the high gear position Hi.

When the low gear Lo is established in the series-parallel HV mode, the controller 100 engages the clutch C1 and releases the brake B1 and the clutch CS. Therefore, the rotating elements (sun gear S1, carrier CA1, and ring gear R1) rotate integrally with each other. Therefore, the ring gear R1 of the transmission unit 40 also rotates at the same rotational speed as the carrier CA1, and the rotation of the engine 10 is transmitted from the ring gear R1 to the carrier CA2 of the differential unit 50 at the same rotational speed. That is, the torque of the engine 10 input to the carrier CA1 of the transmission unit 40 (hereinafter referred to as engine torque Te) is transmitted from the ring gear R1 of the transmission unit 40 to the carrier CA2 of the differential unit 50 . When the low gear position Lo is established, the torque transmitted from the ring gear R1 (hereinafter referred to as the transmission unit output torque Tr1 ) is equal to the engine torque Te (Te=Tr1).

The rotation of the engine 10 transmitted to the carrier CA2 of the differential unit 50 is continuously shifted by using the rotational speed of the sun gear S2 (the rotational speed of the first MG 20 ), and is transmitted to the ring gear R2 of the differential unit 50 . At this time, the controller 100 basically causes the first MG 20 to operate as a generator to apply the first MG torque Tm1 in the negative direction. Thus, the first MG torque Tm1 serves as a reaction force for transmitting the engine torque Te input to the carrier CA2 to the ring gear R2.

The engine torque Te (hereinafter referred to as engine transmission torque Tec) transmitted to the ring gear R2 is transmitted from the auxiliary drive gear 51 to the counter shaft 70 and serves as a driving force of the hybrid vehicle 1 .

In the series-parallel HV mode, the controller 100 causes the second MG 30 to operate mainly as a motor. The second MG torque Tm2 is transmitted from the reduction gear 32 to the counter shaft 70 and serves as a driving force of the hybrid vehicle 1 . That is, in the series-parallel HV mode, the hybrid vehicle 1 runs by using the engine transmission torque Tec and the second MG torque Tm2.

On the other hand, when the high gear Hi is established in the series-parallel HV mode, the controller 100 engages the brake B1 and releases the clutch C1 and the clutch CS. Since the brake B1 is engaged, the rotation of the sun gear S1 is restricted. Thereby, the rotation of the engine 10 input to the carrier CA1 of the transmission unit 40 increases in speed, and is transmitted from the ring gear R1 of the transmission unit 40 to the carrier CA2 of the differential unit 50 . Therefore, when the high gear Hi is established, the transmission unit output torque Tr1 is smaller than the engine torque Te (Te>Tr1).

The controlled state in the series HV mode (line H4 in FIG. 5 ) will be described with reference to FIG. 9 . In series HV mode, controller 100 releases clutch C1 and brake B1 and engages clutch CS. Therefore, when the clutch CS is engaged, the sun gear S2 of the differential unit 50 and the carrier CA1 of the transmission unit 40 rotate at the same rotation speed, and the rotation of the engine 10 is transmitted from the clutch CS to the first MG 20 at the same rotation speed. Thus, it is allowed to generate electric power using the first MG 20 by using the engine 10 as a power source.

On the other hand, since both the clutch C1 and the brake B1 are released, the rotation of each of the sun gear S1 and the ring gear R1 of the speed change unit 40 and the rotation of the carrier CA2 of the differential unit 50 are not restricted. That is, because the transmission unit 40 is in the neutral state and the rotation of the carrier CA2 of the differential unit 50 is not restricted, the power of the first MG 20 and the power of the engine 10 are not transmitted to the countershaft 70 . Therefore, the second MG torque Tm2 of the second MG 30 is transmitted to the counter shaft 70 . Therefore, in the series HV mode, although the first MG 20 generates electricity by using the engine 10 as a power source, the hybrid vehicle 1 runs using the second MG torque Tm2 by utilizing part or all of the generated electricity.

Because the series mode is allowed to be achieved, the operating point of the engine can be selected without worrying about the tooth contact noise of the gear mechanism due to the fluctuation of the engine torque. This tooth contact noise is of concern in mode. Thereby, the vehicle state which can achieve both the quietness of the vehicle and the improvement of the fuel consumption is enhanced.

Next, the arrangement of the speed change unit, the differential unit, the first MG and the clutch will be described. FIG. 10 is a view showing a casing structure of the drive system shown in FIG. 1 . As shown in FIG. 10 , the transmission unit 40 , the differential unit 50 , the first MG 20 and the clutch CS are arranged along the first axis 12 .

Along the first axis 12 , the clutch CS is provided from the engine 10 over the first MG 20 . Among the transmission unit 40 , the differential unit 50 , the first MG 20 , and the clutch CS, the clutch CS is provided at a position farthest from the engine 10 . The transmission unit 40 , the differential unit 50 and the first MG 20 are disposed between the engine 10 and the clutch CS along the first axis 12 . The clutch CS and the first MG 20 are disposed adjacent to each other along the first axis 12 .

The diameter D1 of the clutch CS is smaller than the diameter D2 of the first MG 20 when viewed in the direction of the first axis 12 ( D1 < D2 ). That is, the outermost diameter (diameter D1 ) of the clutch CS is smaller than the outermost diameter (diameter D2 ) of the first MG 20 .

The drive system 2 includes a housing 15 . This case 15 has a box shape, and accommodates components of the drive system 2 such as the transmission unit 40 , the differential unit 50 , the first MG 20 , and the clutch CS.

The housing 15 includes a transaxle (T/A) case 16 and a rear cover 17 . The T/A case 16 has such a shape that the T/A case 16 extends away from the engine 10 in a cylindrical shape while surrounding the transmission unit 40 , the differential unit 50 and the first MG 20 . The T/A shell 16 has openings extending along the first axis 12 . The rear cover 17 is provided so as to close the opening of the T/A case 16 . The rear cover 17 is provided so as to cover the clutch CS protruding from the opening of the T/A case 16 .

The rear cover 17 has as its constituent parts a top portion 17p and a stepped portion 17q. The top portion 17p is arranged so as to face the clutch CS in the direction of the first axis 12 . The step portion 17q is arranged so as to have a step relative to the top portion 17p in the direction of the first axis 12 . The stepped portion 17q has such a concave shape that the stepped portion 17q is concave in a direction approaching the engine 10 from the periphery of the top portion 17p.

With the configuration in which the clutch CS having a smaller diameter than the first MG 20 is arranged on the side away from the engine 10 , the casing 15 can be made compact. More specifically, since the recessed portion is formed at the end in the direction of the first axis 12 by the end face of the first MG 20 and the outer circumference of the clutch CS, the stepped portion 17q is allowed to be provided in the rear cover 17 . Thereby, the space 18 is formed, and the space around the drive system 2 can be effectively used.

In the present embodiment, an oil passage for supplying hydraulic oil to the clutch CS is provided in the housing 15 (rear cover 17 ). By arranging the clutch CS at a position where the clutch CS faces the casing 15 (the rear cover 17 ) in the direction of the first axis 12 , it is possible to easily provide a mechanism for supplying hydraulic oil to the clutch CS through the casing 15 (the rear cover 17 ). mechanism. Therefore, the structure of the oil passage from the hydraulic oil to the clutch CS can be simplified.

In the present embodiment, along the first axis 12 , the differential unit 50 , the first MG 20 and the clutch CS are arranged in the stated order from the side closer to the engine 10 . With the above configuration, it is possible to add the clutch CS to the two-shaft drive system in which the differential unit 50 and the first MG 20 are arranged in the stated order from the side closer to the engine 10 without needing such as increasing the differential unit 50 and the first MG 20 A significant design change in the pitch between the MGs 20 to set the clutch CS.

The arrangement of the transmission unit 40 , the differential unit 50 , the first MG 20 and the clutch CS along the first axis 12 is not limited to the mode shown in FIG. 10 . For example, the clutch CS may be arranged between the differential unit 50 and the first MG 20 , or may be arranged between the transmission unit 40 and the differential unit 50 .

By arranging the position of the clutch CS at the end, it is possible to not connect the drive system for a vehicle with the clutch CS provided and having such a configuration that the series mode is possible and the input shaft 21 and the rotary shaft 22 not provided with the clutch CS from each other The T/A case 16 is shared among the vehicle drive systems of this configuration. Therefore, the manufacturing cost when manufacturing a plurality of models can be reduced.

In the vehicle 1 having the above-described configuration, when switching from the series-parallel mode in which the clutch CS is in the released state and the transmission unit is in the non-neutral state to the series-parallel mode in which the clutch CS is in the engaged state and the transmission unit is in the neutral state, the vehicle 1 changes from The state in which the direct torque of the engine 10 can be transmitted to the drive wheels 90 is changed to a state in which the transmission of power is interrupted between the engine 10 and the drive wheels 90 . Therefore, the direct torque from the engine 10 to the driving wheels 90 is reduced, and thus the driving force of the vehicle 1 can be reduced before and after switching from the series-parallel mode to the series mode.

In the characteristic part of the present embodiment, when the controller 100 is switched from the series-parallel mode to the series mode, the controller 100 controls the shift unit 40 so that the shift unit 40 is placed in a neutral state, and then controls the second MG 30 so that the second MG The output torque of 30 is increased.

With this configuration, it is possible to compensate for the decrease in the direct torque from the engine via the transmission unit 40 to the drive wheels 90 by increasing the output torque of the second MG 30 as the transmission unit 40 gets closer to the neutral state and decrease. Therefore, the reduction in the driving force of the vehicle can be suppressed when the driving mode is switched from the series-parallel mode to the series mode.

Hereinafter, a control process performed by the controller 100 in the case where the driving mode is switched from the series-parallel mode to the series mode in the present embodiment will be described with reference to FIG. 11 .

In step (hereinafter, the step is abbreviated as S) 100, the controller 100 determines whether the driving mode is switched from the series-parallel mode to the series mode. For example, when the state of the vehicle has changed from the series-parallel mode region to the series-parallel mode region, the controller 100 determines that the driving mode is switched from the series-parallel mode to the series mode.

The series-parallel mode region is, for example, a region where the vehicle load (eg, which is calculated from the accelerator pedal operation amount or the like) is a positive value greater than a predetermined load, or a region where the speed of the vehicle is higher than a predetermined speed. The series mode region is, for example, a region where the vehicle load is less than a predetermined load, and a region where the speed of the vehicle is lower than a predetermined speed. The series mode area includes areas where the vehicle load is negative. The series-parallel mode region and the series-parallel mode region are not specifically limited to the aforementioned regions. When it is determined that the driving mode is switched from the series-parallel mode to the series mode (YES in S100 ), the process proceeds to S102 . Otherwise (NO in S100), the process ends.

In S102, the controller 100 reduces the output torque of the engine 10. In the present embodiment, the controller 100 controls, for example, the engine 10 so that the output torque decreases step by step as time elapses according to the output torque just before it is determined that the drive mode is switched from the series-parallel mode to the series mode. The amount of decrease in output torque in each stage is set so as to suppress a sudden increase in the rotational speed of the engine 10 , and is determined, for example, in response to a decrease in reaction torque of the first MG 20 (described later). In the present embodiment, description is made assuming that the reduction of the engine torque at the start of switching from the series-parallel mode to the series mode is performed stepwise; however, the reduction of the engine torque is not particularly limited to the stepwise decrease. Engine torque may decrease linearly or non-linearly. The controller 100 reduces the output torque, for example, by adjusting the opening degree of a throttle valve (not shown) of the engine 10 .

In S104, the controller 100 starts release control for placing the clutch C1 in the release state by reducing the hydraulic pressure supplied to the clutch C1. For example, the controller 100 places the clutch C1 in the released state by reducing the control command value of the hydraulic pressure supplied to the clutch C1 to a predetermined value and then reducing the control command value at a predetermined reduction rate.

In S106, the controller 100 reduces the reaction torque (torque in the negative rotational direction) of the first MG 20 to the output torque of the engine 10. The controller 100 controls the first MG 20 so that the reaction torque decreases stepwise (close to zero) as time elapses according to the reaction torque just before it is determined whether the driving mode is switched from the series-parallel mode to the series mode. The amount of decrease in the reaction torque of the first MG 20 in each stage is set so as to suppress a sudden increase in the rotational speed of the first MG 20 , and is determined, for example, in response to a decrease in the output torque of the engine 10 . In the present embodiment, description is made on the assumption that the reduction of the reaction torque at the time of starting switching from the series-parallel mode to the series mode is carried out step by step with the stepwise reduction of the engine torque; but the reduction of the reaction torque It is not particularly limited to stepwise reduction. The reaction torque can be reduced linearly or non-linearly.

The execution of the above-described processes S102, S104 and S106 is not particularly limited to the order described in the flowchart. The order of execution can be changed.

In S108, the controller 100 increases the output torque of the second MG 30. The controller 100 controls the second MG 30 so that the output torque increases as time elapses according to the output torque just before it is determined that the driving mode is switched from the series-parallel mode to the series mode. When the transmission unit 40 is changed to the neutral state as a result of the clutch C1 being switched from the engaged state to the released state, the direct torque from the engine to the drive wheels 90 via the transmission unit 40 increases as the transmission unit 40 becomes closer to the neutral state. decrease. Therefore, the controller 100 increases the output torque of the second MG 30 to the upper limit of the reduction amount of the direct torque from the engine to the driving wheels 90 . For example, by compensating the entire reduction amount of the direct torque with the output torque of the second MG 30, it is possible to suppress a change in the driving force of the vehicle 1 when the driving mode is switched from the series-parallel mode to the series mode. Alternatively, by compensating for a constant amount of decrease in direct torque with an increase in output torque of the second MG 30 or compensating for a constant rate of decrease in direct torque, it is possible to suppress from series-parallel in the drive mode. Changes in the driving force of the vehicle 1 when the mode is switched to the series mode, while suppressing power consumption due to an increase in the output torque of the second MG 30 . The controller 100 may estimate, for example, the amount of reduction in direct torque based on the hydraulic pressure of the clutch C1 or the hydraulic pressure command value of the clutch C1 or the like.

In S110, the controller 100 determines whether to start synchronization control. The controller 100 determines to start the synchronous control, for example, when a start condition for the synchronous control is satisfied. The start condition may include, for example, a condition that a predetermined time has elapsed from when the drive mode is determined to be switched from the series-parallel mode to the series mode, or from when the drive mode is determined to be switched from the series-parallel mode to the series mode to when the clutch CS is engaged A condition in which the difference between the first rotational speed of the first MG 20 and the second rotational speed of the engine 10 is greater than the threshold value during the period of time. When it is determined that the synchronization control is started (YES in S110), the process proceeds to S112. Otherwise (NO in S110), the process returns to S110.

In S112, the controller 100 controls the first MG 20 so that a positive torque is generated by the first MG 20. Thus, the rotational speed of the first MG 20 increases in the forward rotation direction. The controller 100 controls the first MG 20 so that the output torque of the first MG 20 becomes a predetermined positive torque.

When the first rotational speed of the first MG 20 is lower than the second rotational speed of the engine 10, the controller 100 may increase the rotational speed in the forward rotation direction by generating a predetermined positive torque. When the first rotational speed is higher than the second rotational speed, the controller 100 may increase the rotational speed in the negative rotational direction by generating a predetermined negative torque.

In S114, the controller 100 starts supplying hydraulic pressure to the clutch CS. For example, when a predetermined time has elapsed since the start of the synchronization control, the controller 100 starts supplying hydraulic pressure to the clutch CS. For example, the controller 100 starts to supply hydraulic pressure to such an extent that the clearance can be reduced (removal of dead stroke).

In S116, the controller 100 determines whether the first rotational speed of the rotation shaft of the first MG 20 and the second rotational speed of the output shaft (crankshaft) of the engine 10 are synchronized with each other. For example, when the difference between the first rotational speed and the second rotational speed is smaller than the threshold value, the controller 100 determines that the first rotational speed and the second rotational speed are synchronized with each other. When it is determined that the first rotational speed and the second rotational speed are synchronized with each other (YES in S116 ), the process proceeds to S118 . Otherwise (NO in S116), the process returns to S116.

In S118, the controller 100 places the clutch CS in the engaged state by increasing the hydraulic pressure supplied to the clutch CS to the maximum value. For example, the controller 100 increases the hydraulic pressure supplied to the clutch CS at a predetermined rate of change from when it is determined that the first rotational speed and the second rotational speed are synchronized with each other until a predetermined time elapses, and increases in steps when the predetermined time has elapsed Hydraulic pressure supplied to clutch CS.

The operation of the controller 100 in this embodiment based on the above-described structure and flowchart will be described with reference to FIGS. 12 and 13 .

FIG. 12 shows the changes in the nomogram before and after switching from the series-parallel mode to the series mode. 13 shows the rotational speed of the engine 10, the engine torque, the torque of the first MG 20, the rotational speed of the first MG 20, the rotational speed of the output shaft of the transmission unit 40, the rotational speed of the second MG 20 when switching from the series-parallel mode to the series mode The torque of the MG 30, the rotational speed of the second MG 30, the hydraulic pressure of the clutch C1, the hydraulic pressure of the clutch CS, and the instantaneous changes in the vehicle longitudinal direction G.

For example, it is assumed that the clutch C1 is in the engaged state and both the brake B1 and the clutch CS are in the released state. Assuming that the engine 10 is running, the power generation operation using the first MG 20 is being carried out, and part of the torque of the engine 10 is transmitted to the driving wheels 90 via the differential unit 50 as direct torque.

As indicated by the common line (solid line) in the nomogram of FIG. 12 , because the clutch C1 is in the engaged state, the sun gear S1 , the carrier CA1 and the ring gear R1 in the speed change unit 40 rotate integrally with each other. Since the ring gear R1 and the carrier CA2 are coupled to each other so that the centers of rotation coincide with each other, the sun gear S1 , the carrier CA1 , the ring gear R1 and the carrier CA2 rotate at the same rotational speed as the engine 10 . The engine torque Te of the engine 10 is distributed to the first MG 20 side and the second MG 30 side through the differential unit 50 . Part of the torque distributed to the second MG 30 side of the engine torque Te is transmitted from the engine 10 to the drive wheels 90 as direct torque. Part of the torque of the engine torque Te distributed to the first MG 20 side is used for the power generation operation. The torque Tg in the negative rotational direction is output from the first MG 20 during the power generation operation. In this state, when the engine torque in the forward rotation direction acts on the rotation shaft of the first MG 20 and the first MG 20 rotates in the forward rotation direction, power generation is performed.

As shown in FIG. 13 , at time T( 0 ), it is determined that the driving mode is switched from the series-parallel mode to the series mode due to the fact that the state of the vehicle 1 is switched from the series-parallel mode region to the series-parallel mode region (YES in S100 ) . At time T( 1 ) when a predetermined time has elapsed since the switching was determined, the engine 10 is controlled so that the engine torque is gradually decreased ( S102 ). The hydraulic circuit 500 (specifically, the linear solenoid valve SL1) is controlled so that the hydraulic pressure supplied to the clutch C1 is reduced (S104). In addition, the first MG 20 is controlled such that the torque (reaction torque) of the first MG 20 in the negative rotational direction is gradually decreased (close to zero) (S106).

When the engine torque is further decreased stepwise at time T( 2 ), the rotational speed of the first MG 20 is decreased together with the torque of the engine 10 . Therefore, in the transmission unit 40, each of the rotational speed of the engine 10 and the rotational speed of the first MG 20 is reduced to the position shown by the common line (alternating long and short dashed lines) in the nomogram of FIG. 12 . At this time, the rotational speed of the first MG 20 is smaller than the rotational speed of the engine 10 . Since the transmission unit 40 becomes close to the neutral state as the hydraulic pressure supplied to the clutch C1 decreases, the direct torque transmitted from the engine 10 to the drive wheels 90 via the transmission unit 40 is reduced.

In this case, since the torque of the second MG 30 is increased to the upper limit of the reduction amount of the direct torque ( S108 ), the driving force of the vehicle 1 during the switching of the driving mode from the series-parallel state to the series mode is suppressed of reduction.

The vehicle longitudinal direction G changes in the drive wheel 90 to increase toward the front of the vehicle 1 because of the dissipation of inertia due to the reduction of each of the first rotational speed and the second rotational speed.

At time T(3), when the start condition for the synchronization control is satisfied (YES in S110) due to the fact that a predetermined time has elapsed from the time when the drive mode is determined to be switched from the series-parallel mode to the series mode, the first MG 20 The positive torque increases (S112). Thus, the rotational speed of the first MG 20 increases, and thus the rotational speed of the first MG 20 becomes close to the synchronous rotational speed in the case where the rotational speed of the first MG 20 is synchronized with the rotational speed of the engine 10 . Then, the rotational speed of the first MG 20 increases to the point indicated by the common line (dotted line) in the nomogram of FIG. 12 .

Because of the increase in the positive torque of the first MG 20, the first rotational speed increases. Therefore, due to the traction of inertia, the vehicle longitudinal direction G changes in the drive wheels 90 to increase toward the rear of the vehicle 1 .

At time T(4) when a predetermined time has elapsed since the start of the synchronization control, the engagement control of the clutch CS is started (S114). At time T(5), when the first rotational speed and the second rotational speed are synchronized with each other (YES in S116), the hydraulic pressure supplied to the clutch CS is increased (S118), and the clutch CS is placed at the time T(6) engaged state. Since the engagement of the clutch CS is started at time T(5), the first MG 20 is controlled so as to generate a negative torque corresponding to the power generation amount. At this time, since both the clutch C1 and the brake B1 are in the released state, the engine 10 is disengaged from the drive wheels 90 . On the other hand, because the clutch CS is in the engaged state, the power of the engine 10 can only be transmitted to the first MG 20 via the clutch CS. Therefore, since the power generation torque (reaction torque) is generated in the first MG 20, the power generation operation using the engine 10 as a power source is carried out. At time T(6), when the engine torque increases to a magnitude corresponding to the series mode, the reaction torque of the first MG 20 also increases to a magnitude corresponding to the series mode.

As described above, with the hybrid vehicle according to the present embodiment, it is possible to compensate for the decrease in the direct torque from the engine via the transmission unit 40 to the drive wheels 90 by increasing the output torque of the second MG 30 , which increases with It decreases as the transmission unit 40 gets closer to the neutral state. Therefore, it is possible to provide a hybrid vehicle that suppresses a decrease in driving force when the driving mode is switched from the series-parallel mode to the series mode.

In addition, when switching from the series-parallel mode to the series mode, the controller 100 controls the transmission unit 40 so that the transmission unit 40 is placed in a neutral state, and controls the engine 10 so that the output torque of the engine 10 decreases.

With this configuration, unnecessary increase in the rotational speed of the engine 10 can be suppressed.

Hereinafter, an alternative embodiment regarding synchronization control using the first MG 20 will be described. In the present embodiment, the description is made assuming that the engagement of the clutch CS is started after a predetermined time has elapsed from the start of the synchronization control. Alternatively, for example, the engagement of the clutch CS may start at the start of the synchronization control.

For example, as an alternative to the present embodiment, as shown in FIG. 14 , at time T(3) before time T(4), synchronous control may be started, and supply of hydraulic pressure to clutch CS may be started. FIG. 14 shows a change similar to that of FIG. 13 , except that the change in the vehicle longitudinal direction G is ignored and the timing of the increase in the hydraulic pressure of the clutch CS is different. Therefore, a detailed description thereof will not be repeated.

With this configuration, the time required for switching from the series-parallel mode to the series mode can be shortened compared to when the supply of the hydraulic pressure to the clutch CS is started at the timing shown in FIG. 13 . For example, when a mode requiring high driving force such as a sport drive mode is selected by the driver, it is desirable to perform an operation that advances the timing of starting engagement of the clutch CS.

With this configuration, for example, when the increase of the depression amount of the accelerator or the return of the accelerator is performed by the user, switching from the series-parallel mode to the series mode can be efficiently responded to the user's request.

In the present embodiment, description is made assuming that the clutch CS is engaged when the first rotational speed and the second rotational speed are synchronized with each other after the start of the synchronization control. Alternatively, the control for reducing the torque of at least any one of the first MG 20 and the second MG 30 may be performed at the end of the synchronization control.

When the first rotational speed of the first MG 20 is increased in the synchronous control, as shown in FIG. 15 as an alternative to the present embodiment, the first rotational speed may overshoot near the point where the first rotational speed is synchronized with the second rotational speed The second rotational speed, or the first rotational speed, may oscillate. In this case, when the clutch CS is engaged, a shock may occur, the shock may be transmitted to the driving wheels 90 , and thus, a shock may occur in the vehicle 1 .

For example, as shown in FIG. 15 , when the first rotation speed exceeds the second rotation speed or the difference between the first rotation speed and the second rotation speed becomes smaller than a threshold value (a value larger than the threshold value for determining synchronization) at time T(7) , the controller 100 may reduce the output torque of the second MG 30 by a predetermined value before the time T(8) at which the difference between the first rotational speed and the second rotational speed converges. Instead of or in addition to the decrease in the output torque of the second MG 30, the controller 100 may compare the torque of the first MG 30 with the torque before time T(7). torque decreases by a predetermined value. This value does not need to be constant. For example, when the difference between the first rotational speed and the second rotational speed is smaller than a threshold value for determining synchronization and when the instantaneous change amount (eg, change amount per unit time) of the difference per predetermined time is smaller than the threshold value, the controller 100 It can be determined that the difference between the first rotational speed and the second rotational speed has converged.

With this configuration, since the torque fluctuation is suppressed due to the engagement of the clutch CS, it is possible to smoothly switch from the series-parallel mode to the series mode.

Alternative Embodiments of Control for EV Mode and HV Mode

As described in the control mode shown in FIG. 5 , when the engine 10 and the first MG 20 are directly coupled to each other by means of the clutch CS in the HV mode and the shift is shifted by placing both the clutch C1 and the brake B1 in the released state When the unit 40 is controlled to the neutral state, the vehicle can be operated in series mode.

Hereinafter, the fact that the vehicle can be caused to run in a further operating mode by using the clutch CS will be described.

FIG. 16 shows still another alternative embodiment of the present embodiment and is a graph showing the controlled states of the clutch C1 and the brake B1 of the transmission unit 40 in each driving mode.

In FIG. 16 , lines E4 and E5 are added to the EV mode in FIG. 5 , and lines H6 to H9 are added to the HV mode in FIG. 5 . The symbols in FIG. 16 have similar meanings to those in FIG. 5 .

Initially, the description will be added to the E4 line and the E5 line of the EV mode. These additional modes, as well as row E3, are dual motor modes and differ from row E3 in that these additional modes are operable even when the engine speed Ne is not zero (Ne free in Figure 16).

FIG. 17 is a nomogram for illustrating the operations of the E4 row and the E5 row in FIG. 16 . The controlled state in the dual-motor EV mode will be described with reference to FIG. 17 . FIG. 17 illustrates a case where the vehicle is traveling forward in the low gear Lo (see the shared solid line shown in FIG. 17 ) and the case where the vehicle is traveling at the high gear Hi (see the shared dotted line shown in FIG. 17 ). For convenience of description, it is assumed that the rotational speed of the ring gear R1 is the same whether the vehicle is traveling forward in the low gear position Lo or when the vehicle is traveling forward in the high gear position Hi.

When the low gear Lo is established in the dual-motor EV mode (row E5 in FIG. 16 ), the controller 100 engages the clutch C1 and the clutch CS, and releases the brake B1 . Therefore, the rotation elements (sun gear S1 , carrier CA1 and ring gear R1 ) of the speed change unit 40 rotate integrally with each other. When the clutch CS is engaged, the carrier CA1 of the transmission unit 40 and the sun gear S2 of the differential unit 50 rotate integrally with each other. Thus, all the rotating elements of the speed change unit 40 and the differential unit 50 are integrally rotated at the same rotational speed. Therefore, when the first MG torque Tm1 is generated in the forward rotational direction by the first MG 20 together with the second MG 30, the hybrid vehicle 1 can be caused to run by using these two electric motors. Because the engine 10 is not autonomously driven in the EV mode, the engine 10 is in a driven state in which the engine 10 is driven by the torques of both the first MG 20 and the second MG 30 . Therefore, it is desirable that the opening/closing timing of each valve can be operated so that resistance during rotation of the engine is reduced.

The first MG transmission torque Tm1c transmitted to the ring gear R2 is transmitted from the auxiliary drive gear 51 to the counter shaft 70 and serves as a driving force of the hybrid vehicle 1 . At the same time, the second MG torque Tm2 is transmitted from the reduction gear 32 to the counter shaft 70 and serves as the driving force of the hybrid vehicle 1 . That is, when the low gear position Lo is established in the dual-motor EV mode, the hybrid vehicle 1 travels by using the second MG torque Tm2 and the first MG torque Tm1 transmitted to the ring gear R2.

On the other hand, when the high gear Hi is established in the dual-motor EV mode (row E4 in FIG. 16 ), the controller 100 engages the brake B1 and the clutch CS, and releases the clutch C1 . Because the brake B1 is engaged, the rotation of the sun gear S1 is restricted.

Because the clutch CS is engaged, the carrier CA1 of the transmission unit 40 and the sun gear S2 of the differential unit 50 rotate integrally with each other. Therefore, the rotational speed of the sun gear S2 is equal to the rotational speed of the engine 10 .

FIG. 18 is a nomogram for illustrating the operations of rows H6 to H9 in FIG. 16 . The controlled state in the two-motor HV (parallel mode: stepped) mode will be described with reference to FIG. 18 . FIG. 18 illustrates a case where the vehicle is traveling forward in the low gear Lo (see the common solid line shown in FIG. 18 ) and the case where the vehicle is traveling in the high gear Hi (see the common broken line shown in FIG. 18 ).

As is apparent from the comparison between FIGS. 17 and 18 , in the dual-motor HV (parallel mode; stepped) mode, the engine 10 is driven autonomously, and thus the engine torque Te is applied to the planet carrier CA1 as shown in FIG. 18 . Therefore, the engine torque Te is also added to the ring gear R2. The remaining points of the nomogram shown in FIG. 18 are the same as those in FIG. 17, and thus the description will not be repeated.

In the dual-motor HV (parallel mode: stepped) mode, the engine torque Te, the first MG torque Tm1 and the second MG torque Tm2 are all allowed for the forward rotational torque of the drive wheels, so when the drive wheels require Especially effective at large torques.

The controlled state in the single-motor HV (parallel mode: stepped) mode corresponds to the case of Tm1=0 in FIG. 18 .

Next, an alternative embodiment of the gear mechanism will be described. FIG. 19 shows a first alternative embodiment of the gear mechanism of the hybrid vehicle of FIG. 1 . As shown in FIG. 19 , in the hybrid vehicle 1A according to the present alternative embodiment, the transmission unit 40 includes a double pinion type planetary gear mechanism, a clutch C1 and a brake B1 . The double pinion type planetary gear mechanism includes a sun gear S1, a pinion gear P1A, a pinion gear P1B, a ring gear R1, and a carrier CA1.

With this configuration, a larger gear ratio width can be set with mountability equivalent to that of the speed change unit 40 including the single-pinion type planetary gear mechanism.

FIG. 20 is a view showing a second alternative embodiment of the gear mechanism of the hybrid vehicle in FIG. 1 . As shown in FIG. 20 , in the hybrid vehicle 1B according to the present alternative embodiment, the hybrid vehicle is a pre-engine that travels by using the power of at least any one of the engine 10 , the first MG 20 and the second MG 30 . rear-wheel drive (FR) hybrid vehicle.

The first MG 20 and the second MG 30 are disposed coaxially with the crankshaft of the engine 10 along the first axis 12 . The speed change unit 40B, the differential unit 50B, the clutch CS and the reduction unit 55 are further arranged along the first axis 12 . The speed change unit 40B, the clutch CS, the first MG 20 , the differential unit 50B, the second MG 30 and the reduction unit 55 are arranged in the stated order from the side closer to the engine 10 .

The first MG 20 is provided so that power from the engine 10 can be input to the first MG 20 . More specifically, the input shaft 21 is connected to the crankshaft of the engine 10 . The carrier CA1 of the speed change unit 40B is connected to the input shaft 21 and integrally rotates with the input shaft 21 . The carrier CA1 of the transmission unit 40B is connected to the rotation shaft 22 of the first MG 20 via the clutch CS.

The clutch CS is provided in the power transmission path from the engine 10 to the first MG 20 . The clutch CS is a hydraulic friction engagement element capable of coupling the rotary shaft 22 of the first MG 20 to the carrier CA1 of the transmission unit 40B that rotates integrally with the input shaft 21 . When the clutch CS is placed in the engaged state, the carrier CA1 and the rotary shaft 22 are coupled to each other, thus allowing power transmission from the engine 10 to the first MG 20 . When the clutch CS is placed in the released state, the coupling of the carrier CA1 with the rotary shaft 22 is released, and thus power transmission from the engine 10 to the first MG 20 is interrupted.

The output shaft 70A extends along the first axis 12 . The output shaft 70A is connected to the ring gear R2 of the differential unit 50B, and rotates integrally with the ring gear R2.

The reduction unit 55 includes a single-pinion type planetary gear mechanism including a sun gear S3, a pinion gear P3, a ring gear R3, and a carrier CA3. The rotation shaft 31 of the second MG 30 is connected to the sun gear S3. The rotation shaft 31 of the second MG 30 rotates integrally with the sun gear S3. The ring gear R3 is fixed to the housing of the drive system. The output shaft 70A is connected to the planet carrier CA3. The output shaft 70A rotates integrally with the carrier CA3. The rotation of the output shaft 70A is transmitted to the left and right drive shafts (not shown) via a differential unit (not shown).

In this alternative embodiment, the drive system can be mounted on an FR hybrid vehicle by arranging the output shaft 70A coaxially with the crankshaft of the engine 10 .

The above-described embodiments are in all respects illustrative and not restrictive. The scope of the invention is defined by the appended claims rather than the above description. The scope of the invention is intended to cover all modifications within the scope of the appended claims and their equivalents.

Claims (3)

1. a kind of hybrid vehicle, characterized by comprising:

Internal combustion engine；

First rotating electric machine；

Second rotating electric machine is configured to output power to driving wheel；

Power transfer unit comprising input element and output element, the input element are configured to connect from the internal combustion engine Power is received, the output element is configured to that the power output of the input element will be input to, and power transmitting is single Member is configured to switch between non-neutral state and neutral state, and in the non-neutral state, power is in the input element It transmits between the output element, in the neutral state, is not transmitted between the input element and the output element Power；

Differential unit comprising the first rotating element, the second rotating element and third rotating element, first rotating element connect It is connected to first rotating electric machine, second rotating element is connected to second rotating electric machine and the driving wheel, described Third rotating element is connected to the output element, and the differential unit is constructed such that: when being determined described first When the revolving speed of rotating element, second rotating element and any two in the third rotating element, first rotation Remaining one revolving speed in element, second rotating element and the third rotating element is determined；

Clutch is configured to switch between engagement state and release conditions, and in the engagement state, power is from described interior Combustion engine is transferred to first rotating electric machine, in the release conditions, interrupts from the internal combustion engine to first rotating electric machine Power transmitting, the power from the internal combustion engine is passed to institute by least one of first path or the second path State the first rotating electric machine, the first path be power from the internal combustion engine via the power transfer unit and the differential list Member is transferred to the path that first rotating electric machine is passed through, and second path is that power is transferred to from the internal combustion engine The path that first rotating electric machine is passed through, second path is different from the first path and does not include described differential Unit, and the clutch is arranged in second path；And

Controller is configured to: when switching from series-parallel mode to series model, starting to control the power transmitting list Member is placed in the power transfer unit after the neutral state, controls second rotating electric machine so that described second The output torque of rotating electric machine increases, and the series-parallel mode is that the clutch is in the release conditions and the power Transfer unit is in the mode of the non-neutral state, the series model be the clutch be in the engagement state and The power transfer unit is in the mode of the neutral state.

2. hybrid vehicle according to claim 1, it is characterised in that

The controller is configured to: until when the clutch is placed in the engagement state, controlling first rotation In motor and second rotating electric machine at least any one so that being placed in the engagement state as by the clutch As a result the torque ripple occurred reduces.

3. hybrid vehicle according to claim 1, it is characterised in that

The controller is configured to: when switching from the series-parallel mode to the series model, the power being transmitted Unit is placed in the neutral state and reduces the output torque of the internal combustion engine.